Category Archives: Practical stuff

Ever been sunburned? Gone to bed with that awful, sweaty, stinging feeling of hot regret? Had little blisters form then pop? We pretty much all have haven’t we. Stupid bastards that we are! “Stupid” because that ol’ friend of ours, our nearest star, our planet’s parent and orbital centre, The Sun, puts out a lot of energy. Just how much; well obviously enough to broil your shoulders at some point!

As this picture clearly shows, you can work out the energy received at any given point using this simple formula:

“, the theoretical daily-average insolation at the top of the atmosphere, where θ is the polar angle of the Earth’s orbit, and θ = 0 at the vernal equinox, and θ = 90° at the summer solstice; φ is the latitude of the Earth. The calculation assumed conditions appropriate for 2000 A.D.: a solar constant of S0 = 1367 W m−2, obliquity of ε = 23.4398°, longitude of perihelion of ϖ = 282.895°, eccentricity e = 0.016704. Contour labels (green) are in units of W m−2.”

Got that? Clearly though this formula doesn’t account for the various ways that the Earth’s atmosphere absorbs and scatters the energy as it travels from the outer edge of the atmosphere to ground level. That varies depending on cloud cover and other suspended moisture, suspended particulates, vegetation and so on. So lets just sum it all up and say that the sun puts out a lot of energy and on a hot, clear day you could fry an egg very, very quickly using just the sun’s heat.

Which brings us to this little conundrum; what do you do with an old satellite (internet) dish that has been superseded with a newer, faster model?

Do you;

Give it to the dish-installer man to take away and dispose of?

Turn it into a very large birdbath?

Leave it forever behind the garage until the Missus yells “Clean that shitpile up!”

Use it to make mischief (in a fun, harmless way of course)?

Guess which numbered box the money is in….you betcha….Number 4!

There are quite a few YouTube videos of people making reflector dishes out of old sat’ dishes. Many of them use the little, square mirrors, like off a disco mirror ball. All I can say is that they must be richer than me, or at least more willing to throw money at a simple, fun project. At the cheapest price I could find those mirror squares for sale the total cost for enough of them would have been $400-$500. No way José!!

Reflective Mylar film is another matter – a roll of that comes in about $40-$50. The overall reflective properties probably aren’t quite as good as a set of glass mirrors (Mylar film comes in at about 92-97% reflectivity, not too different than mirrors as the actual reflective material in a mirror is basically the same stuff; however the Mylar film is impossible to adhere to the dish without some imperfections resulting, such as ripples, bubbles and some areas of glue overspray) and of course the film won’t be weatherproof so the dish will have to be stored indoors. However these cons just pale into insignificance against the cost savings.

The film was cut into (roughly) triangular shapes to allow us to better shape it into the dish. To glue the film to the dish we used a spray adhesive, masking off each previously glued section to prevent (OK…minimise) overspray.

Here is the completed dish, mounted on the post, leg spars and roof brackets that were intended to actually put the original dish on a roof, and are here slightly modified to provide a stable, free-standing base.

It all looks very innocent. Looks can however be deceiving…

More mayhem….errrr….I mean “Scientific Experiments of an Educational Nature” videos to come. The video above was our first “experiment” which was performed at around 2:30pm mid September. Can’t wait for mid-Summer at between 11am and 1pm (solar time).

Warning – try this at home.

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I admit it…I’ve been sulking for a little while. I’d thrown my safety goggles out of the pram. Downed tools. Generally turned my back on the Coffee Table project. You see….someone had been twisting my leg!

A while back I did a “finish sand” over all the surfaces of the first set of legs, dowelled them up, and braced and glued them. Here they are;

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One of the legs had a lovely, feature “bolt hole” for which this length of timber had been selected. All that remained to be done with this leg set was to give it a final finish-sand, especially to remove excess glue around the joints. All good!

Except….I’d put the legs on the wrong way! As you may see in the “middle” picture the leg timbers are rectangular, not square. In this leg-set I dowelled the crossbeam into the short side of the legs, not the wide side. This error is more than simply one with aesthetic implications, as it makes the overall leg set too wide for the table top.

Bugger-ation!!

No way to redeem this now – it just goes into the newly created “Collection of very nice H-shaped timber pieces that may one day be useful” pile. I’m rather hoping to not add too much more to that collection!

Oh well….after a little sulk it’s time to cut two more legs and start again!

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Down the side of the storage area for the trailer is a pile of shitty, old, nail spiked lengths of hardwood timber; the remnants of an old deck that was pulled down a while back. This pile represents the timbers that had a solid feel to them when they were removed, indicating that beneath their rotten exteriors a heartwood of strength beats still.

That there is a classic before and after photo, without the aid of coy staging or Photoshopping. The timbers the old piece is sitting on are ten or so lengths that have already been trimmed and planed.

About a year or so ago one of the lengths had already been through this process and proven its worthiness as a member of my “long solid bits of naily, seemingly rotten timber that might someday be useful for something” collection having been transformed into a rather awesome ceremonial staff-like object for a friend’s 50th birthday (“rather awesome” even if I do say so myself!).

The rest of the pile however just sat there with a dejected sort of expression that clearly meant “Hurry up and turn me into something you lazy, procrastinating bastard”. I could tell it all just was desperate to channel its inner coffee table – I dunno…sometimes you can just tell these things even if you can’t normally speak fluent Entish.

And so has begun the quite possibly long process of building a coffee table. Knowing as I do your intense curiosity as to the status of the project, here are some exciting action photos:

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Fire season approaches and after a few years of rainy years the fuel load has built up everywhere. This year the ENSO cycle is swinging us towards a baking and rainless summer, and we’re therefore expecting a hot, dry, dangerous season of bush fires. Time to clear some wind fall and maintain what the NSW RFS terms the Asset Protection Zone (APZ).

Last year there were a few burn piles I had built but then ran out of time to light up before we hit the summer fire-permit season. As well as getting through those I have also a few more new piles to build – all up we’re probably looking at about 7 burn piles before the summer officially starts.

Burn pile

“Never start a fire you can’t put out” are wise words – so there is a bit of prep’ do before the matches come out. As the first pile is down the North East slope at the outer edge of the APZ this means setting up Davey as close to the pile as possible whilst still having a water feed handy, then running a hose down to the pile which is built about 50m from that pump location. Davey is being fed by the new header tank which has been filled as well, giving 10,000l of drenching ability should things go not-to-plan.

Once the pump is ready the next step is to do a final clear around the pile with the fire rake, gear up in jeans, boots, wool jumper, leather hat, fire goggles, fire gloves and a protective wrap covering the face/neck/ears. That sounds very over he top until you’ve stood next to a burn pile at full fury – it’ll singe skin within seconds at distances less than 2 metres. The neighbours already having been warned to not panic at smoke columns it’s time to go. A little splash of diesel, flame introduced by way of gas powered, metre long fire wand….and….

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At the South Western corner of the house there is a bank rising about a metre and a half or so, sloped outward at 45 degrees. Its a natural shortcut when heading to the garage, though perhaps not when carrying things as the ground can be slippery when damp. A few metres to the right there are some rough stone steps, constructed I guess when the house was built some 30 years ago. The shortcut was so much used it had clearly proved worthy of being formalised and honoured with some steps of its own.

Steps need to be solid, and solid means big rocks, and big rocks means “bloody hell…that’s heavy <insert sound here of the sound of the kurfuffle valve rupturing>”. The bottom step forms the base for all the others and of course needs to be biggest, heaviest, kurfuffle-valve-blowingest stone of all. Here it is weighting* to be placed in position.
So you can appreciate it better here is another view. To get this stone to this point required dragging it with a chain on a steel drag sheet, using the Scooby Doo. Even it called for a plate of fresh Scooby Snacks afterwards.

Another view of what will be the bottom step – she’s a monster

Getting the first stone into place basically involved two careful stages: firstly dig out a stone shaped hole; and secondly roll the stone off the slope and hope the best it landed roughly in the right place. Fortunately it did, and after just a little bit of juggling we were ready for the next.

This photo is a bit blurry. I think my kurfuffle valve was still erupting at this point.

And we’re done. Phew. Just a bit of tidying up to do and we’re ready to take the next step. **

* Can you see what I’ve done there? Can you? Or did you think I made an accidental spelling error?

** Can you see what I’ve done there? Golly I’m funny.

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On the back of a six month dry spell due to the ENSO cycle and a climate change intensified heat wave, the scorching heat of Sydney’s hottest ever recorded day evaporated away much of the water in the dam. With just a few inches left in the dam, no more was available to pump up to the irrigation header tank – all that was left was water too oozy and muddy to pump, and anyway the frogs needed something to keep their chorusing throats wet. The irrigation for the veggie patches got switched over to tank water supply, not ideal but better than having all the effort and resources put into the veggies going to waste because they’d dried out under the hot sun.

The tanks are our water supply for all domestic uses, plus fire fighting and general (non plant) garden use. If the tanks run dry we would have to buy water in; something we’ve never had to do in the past and hopefully won’t have to in the future. Water trucked in comes with a relatively high financial cost per litre (well, especially when you’re not paying anything for the water you collect yourself), a high environmental cost (processing and transport), and has the added taste disadvantage of being town, chlorinated water.

Just as the summer school holidays are coming to a close however Tropical Storm Oswald has hammered far North Queensland with rain and wind, flooded Brisbane and the surrounding suburbs, whipped up the oceans with shore battering energy, and is slowly making its way down South to share the joy before drizzling itself out somewhere South of Sydney in a few days time.

Just above the target’s bullseye of the rain radar map you can see Gosford labelled, whilst slightly up and left you can see Putty. ridgesong lies roughly halfway between these two markers and boy, are we appreciating Oswald’s legacy. Just before the first of the rain hit we did some water management, moving water from the garage tank to the (more heavily and regularly used) house tank, in order to ensure that both tanks had space to collect more rainfall. After all, there is no point getting rain if your tank is already full and it’s all just pouring down the side.

After spending the weekend boating on the Hawkesbury we returned home last night to find both tank’s overflowing and the dam level about 15cms higher than before. Not bad at all. This morning, with another 80mm to 100mm of rain due I groomed the slope leading to the dam with a hoe and shovel to ensure that we maximise the water flow from the drive at the top of the hill (in front of the neighbour’s house) into the dam. Meanwhile I pumped some water (approx. 10,000L) up from the house tank to the already full garage tank, causing it to then overflow into the dam. That put another 10cms or so of level into the dam. We expect that by tomorrow morning, once the storm has expending itself, the house tank will again be overflowing. To put all this into perspective, by the time this storm system passes us we will have collected approximately 25,000L of water. Lots of people are suffering because of Oswald’s fury, and at least one person has lost his life, but down here in our little patch of the Earth we are very grateful for the rain. Collecting your own water makes you exceedingly conscious of how much you use, and very mindful that rainy days are more than a reason to grumble and moan about being stuck inside. Climate predictions point to a drier future for Australia as a whole, so collecting water while the rain falls is not just a simple distraction from the grey drizzle on a rainy day, it is life and opportunity while we can enjoy it and something that will become only more important as time goes on.